Unless you're a hardcore gamer type, you've probably never heard of Ageia and their PhysX processor. This add-on card for your desktop PC works with certain supported games to provide additional processing power for in-game physics, leading to bigger explosions, more interactive environments, etc.
Of course, there are only a handful of games that support PhysX (Ghost Recon Advanced Warfighter 2, and Unreal Tournament 3 are the only notable ones that come to mind), and game developers aren't exactly lining up to create extra content for a proprietary physics system that very few consumers will ever be able to experience, but they at least get points for trying.
Now Ageia has announced the PhysX 100M, the company's first physics chip for laptops. The new part is specially designed for mobile computers and, according to Ageia, "features incredibly low power and thermal design with power dissipation of nearly 10W under gameplay conditions. It also includes active power management to throttle down the clock in high heat system conditions and reduce the clock when not active."
We know of at least one big-name gaming laptop hitting the market soon that will offer this as an option, but so far, adoption on the desktop side has been slow, so don't expect this to be a must-have add-on for your next laptop.